JP2008166377A - Manufacturing method for printed circuit board, printed circuit board and reinforcing electronic part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a printed circuit board capable of efficiently reinforcing the bonding strength of an electronic part to a printed wiring board. <P>SOLUTION: The manufacturing method for the printed circuit board has a preparation process (a) preparing the printed wiring board 22 with a mounting region for mounting the electronic part 21 and an adhesive loading process (b) loading a solid adhesive 24 in the mounting region of the printed wiring board 22 prepared by the preparation process. The manufacturing method for the printed circuit board further has a part loading process (c) superposing and loading an electrode forming surface 21s to the solid adhesive 24 in the direction crossing the electrode forming surface 21s of the electronic part 21 as a process loading the electronic part 21 on the printed wiring board 22 through the adhesive loading process and a heating process (d) reflow-heating the printed wiring board 22 through the part loading process. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a printed circuit board on which electronic components are mounted, a printed circuit board, and a reinforced electronic component mounted on the printed circuit board.

Electronic circuits use printed circuit boards in which electronic components such as semiconductor components and surface mount components are mounted on printed wiring boards. Electronic components as semiconductor components include BGA (Ball Grid Array), LGA (Land Grid Array), CSP (Chip Size Package), and QFN (Quad) for high-density mounting of components and shortening of transmission lines. Flat NON-leaded packages) and packages having electrodes on the lower surface such as bare chips are widely used. It is known to inject a resinous adhesive (underfill) between an electronic component and a printed wiring board in order to reinforce a joint portion of this type of electronic component. As an example, there is an electronic component mounting method in which an electronic component is mounted after applying a resinous adhesive to a predetermined portion of a printed wiring board, that is, a printed circuit board manufacturing method (see, for example, Patent Document 1). .
2002-271014 gazette

  However, in the method for manufacturing a printed circuit board described in Patent Document 1, a resin adhesive application step using a syringe is required in addition to a component mounting step using a mounter, which increases the cost as well as the manufacturing step. End up.

  Accordingly, an object of the present invention is to provide a printed circuit board manufacturing method, a printed circuit board, and a reinforced electronic component that can efficiently reinforce the bonding strength of the electronic component to the printed wiring board.

  The printed circuit board manufacturing method of the present invention includes (a) a preparation step of preparing a printed wiring board having a mounting region for mounting electronic components, and (b) a mounting region of the printed wiring board prepared by the preparation step. An adhesive mounting step of mounting the solid adhesive on the substrate, and (c) a step of mounting the electronic component on the printed wiring board that has undergone the adhesive mounting step, in the direction intersecting the electrode forming surface of the electronic component. And a component mounting step of stacking on the solid adhesive, and (d) a heating step of reflow heating the printed wiring board that has undergone the component mounting step.

  In another printed circuit board manufacturing method of the present invention, (a) a preparation step of preparing a printed wiring board having a mounting area for mounting an electronic component, and (b) an electronic component are prepared by the preparation step. Mounting on the printed wiring board, mounting the electronic component with the electrode forming surface facing the mounting area of the printed wiring board, and (c) at the edge of the electronic component that has undergone the component mounting process It has the adhesive mounting process which mounts a solid adhesive, and (d) the heating process which reflow-heats the printed wiring board which passed through the adhesive mounting process, It is characterized by the above-mentioned.

  The reinforced electronic component of the present invention is an electronic component having an electrode on the electrode forming surface, a bump bonded to the electrode of the electronic component, a substantially rectangular solid at room temperature, and has thermoplasticity. And a solid adhesive bonded to the electrode forming surface.

  Further, another reinforced electronic component of the present invention includes an electronic component having an electrode on the electrode forming surface, a bump bonded to the electrode of the electronic component, a covering portion that covers the edge of the electronic component at room temperature, and an electrode of the electronic component It is a solid having an inverted L-shaped cross section having a protruding portion protruding from the forming surface, has thermoplasticity, and has a solid adhesive bonded to the edge of the electronic component.

  Furthermore, another reinforcing electronic component of the present invention includes an electronic component having an electrode on the electrode forming surface, a bump bonded to the electrode of the electronic component, a covering portion covering the edge of the electronic component, and an electrode forming surface of the electronic component. And a reinforcing member joined to the edge of the electronic component.

  The printed circuit board of the present invention is a printed circuit board in which an electronic component having an electrode on an electrode forming surface facing the printed wiring board is mounted on the printed wiring board. This printed circuit board is a bump that joins the electrodes of the electronic component and the printed wiring board, is a substantially rectangular solid at room temperature, and has thermoplasticity, and is provided between the electronic component and the printed wiring board. And a solid adhesive bonded to the electrode forming surface of the electronic component and the printed wiring board after reflow overheating.

  Another printed circuit board according to the present invention includes a bump for joining the electrode of the electronic component and the printed wiring board, a covering portion that covers the edge of the electronic component at room temperature, and the electrode forming surface of the electronic component to the printed wiring board. It is a solid with an inverted L-shaped cross section having a protruding portion that protrudes toward the end, and has thermoplasticity, and is provided at the edge of the electronic component, and on the edge of the electronic component and the printed wiring board after reflow overheating Solid adhesive to be joined.

  Furthermore, another printed circuit board of the present invention is a printed circuit board in which reinforcing electronic components are mounted on a printed wiring board. The reinforced electronic component in this printed circuit board includes an electronic component having an electrode on the electrode forming surface facing the printed wiring board, a bump bonded to the electrode of the electronic component, a covering portion covering the edge of the electronic component, and the electronic component And a reinforcing member that is bonded to the edge of the electronic component and is bonded to the printed wiring board after reflow overheating. Prepare.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a printed circuit board, the printed circuit board, and the reinforcement electronic component which can reinforce efficiently the joining strength of the electronic component with respect to a printed wiring board can be obtained.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.
[First Embodiment]

  FIG. 1 is a perspective view illustrating an electronic apparatus according to the first embodiment. An electronic device 10 shown in FIG. 1 is a notebook personal computer, and includes a computer main body 11 and a display unit 12.

  The computer main body 11 has a thin box-shaped housing. On the top surface thereof, a keyboard 13, a power button 14 for turning on / off the electronic device 10, an input operation panel 15, and a touch A pad 16 and a speaker 18 are provided. The computer main body 11 is provided with a display unit 12.

  The display unit 12 incorporates a display device composed of an LCD (Liquid Crystal Display) 17, and the display screen of the LCD 17 is positioned substantially at the center of the display unit 12. The display unit 12 is attached to the computer main body 11 so as to be rotatable between an open position and a closed position.

  Inside the computer main body 11, a printed circuit board that includes electronic components such as a memory and a CPU and that constitutes an electronic circuit for executing various programs stored in the memory and realizing various functions is disposed. .

  FIG. 2 is a view showing the printed circuit board according to the first embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along line III-III in the printed circuit board shown in FIG. FIG. 3A shows the printed circuit board before reflow, and FIG. 3B shows the printed circuit board after reflow. As shown in FIGS. 2 and 3, the printed circuit board 20 is a printed circuit board mounted inside the computer main body 11 described above, and includes an electronic component 21, a printed wiring board 22, a solder bump 23, and a solid body. And an adhesive 24.

  The electronic component 21 is a semiconductor component such as a memory or a CPU. The electronic component 21 includes an integrated circuit inside and is packaged as a BGA (Ball Grid Array), an LGA (Land Grid Array), a CSP (Chip Size Package), a QFN (Quad Flat NON-leaded Package), or a bare chip. Parts. An electrode 21a is provided on the electrode forming surface 21s side of the electronic component 21, and the electronic component 21 is mounted on the component mounting surface 22s of the printed wiring board 22 via the solder bumps 23 joined to the electrode 21a. ing.

  The printed wiring board 22 is provided with wiring electrodes 22a for alternately connecting wiring layers and dielectric layers to be connected to the electrodes 21a of the electronic component 21 mounted on the component mounting surface 22s. A solder paste 31 is applied on the wiring electrode 22 a, and the wiring electrode 22 a is connected to the solder bump 23 via the solder paste 31.

  The solder bump 23 is provided between the electrode 21a of the electronic component 21 and the wiring electrode 22a of the printed wiring board 22, and connects these electrodes 21a and 22a. As shown in FIGS. 3A and 3B, the solder bump 23 is melted at the time of reflow, and the electrodes 21a and 22a are joined together integrally with the melted solder paste 31. At this time, the solder bumps 23 are deformed by subsidence due to the weight of the electronic component 21.

  In the present embodiment, the solid adhesive 24 is provided between the electronic component 21 and the printed wiring board 22 at the four corners of the electronic component 21 in order to reinforce the bonding strength of the electronic component 21 to the printed wiring board 22. Yes. As shown in FIG. 3A, the solid adhesive 24 is a substantially rectangular solid at room temperature, and is an adhesive having thermoplasticity. The melting temperature of the solid adhesive 24 is equal to or lower than the melting temperature of the solder bump 23. Therefore, as shown in FIG. 3B, the solid adhesive 24 melts at the time of reflow and is deformed by sinking due to the weight of the electronic component 21, and the corners of the electronic component 21 and the printed wiring board 22. The electronic component 21 and the printed wiring board 22 are fixed by adhering to the component mounting surface 22s.

  The height H24 of the solid adhesive 24 before reflowing (before melting), that is, at room temperature, is the distance H23a between the electrode forming surface 21s of the electronic component 21 and the component mounting surface 22s of the printed wiring board 22 after reflowing (after melting). The above is preferable. In other words, the height H24 of the solid adhesive 24 before reflowing is preferably equal to or higher than the height of the solder bumps 23 after reflowing. According to this, the solid adhesive 24 can be favorably adhered to the corner of the electronic component 21 and the component mounting surface 22 s of the printed wiring board 22 during reflow.

  Further, the height H24 of the solid adhesive 24 before reflowing is preferably not more than 5 times the distance H23a between the electrode forming surface 21s of the electronic component 21 and the component mounting surface 22s of the printed wiring board 22 after reflowing. In other words, the height H24 of the solid adhesive 24 before reflowing is preferably not more than 5 times the height of the solder bumps 23 after reflowing. According to this, at the time of reflow, the connection reliability between the electrodes 21a and 22a by the solder bump 23 is not lowered without inhibiting the sinking of the electronic component 21.

  In addition, it is preferable that the surface which contacts the component mounting surface 22s of the printed wiring board 22 in the solid adhesive 24 has adhesiveness. According to this, the deviation of the solid adhesive 24 can be prevented after being mounted on the printed wiring board 22.

  Below, a suitable example of the printed circuit board 20 is shown. When the interval P21 between the electrodes 21a of the electronic component 21 is 1.0 mm, a solder bump 23 having a diameter before reflow of 0.6 mm is used, and the distance from the electrode forming surface 21s of the electronic component 21 to the tip of the solder bump 23 is used. The height H23b before reflow is 0.4 mm to 0.5 mm. Note that the thickness H31 of the solder paste 31 is 0.1 mm to 0.2 mm.

  After the reflow, the distance H23a between the electrode forming surface 21s of the electronic component 21 and the component mounting surface 22s of the printed wiring board 22 is 0.2 mm to 0.3 mm due to the sinking caused by the weight of the electronic component 21. At this time, the height H24 of the solid adhesive 24 before reflowing is preferably 0.2 mm to 0.3 mm or more.

  In addition, since some electronic components 21 such as a CPU reach a temperature of about 90 degrees when the CPU is activated, the melting temperature of the solder bumps 23 and the solder paste 31 is about 220 degrees. The melting temperature of the solid adhesive 24 does not hinder sinking due to the weight of the electronic component 21, and the melting temperature of the solid adhesive 24 is 100 degrees to 220 so that the solid adhesive 24 does not soften at the temperature when the CPU is activated. Is preferred.

  Next, a procedure for mounting the electronic component 21 on the printed wiring board 22, that is, a printed circuit board manufacturing method according to the first embodiment of the present invention will be described. FIG. 4 is a diagram showing a method for manufacturing a printed circuit board according to the first embodiment of the present invention.

  First, as shown in FIG. 4A, a printed wiring board 22 having a mounting area for mounting the electronic component 21 is put into a component mounting line, and a solder paste 31 is placed on the wiring electrode 22a on the component mounting surface 22s side. Is printed (preparation step).

  Next, as shown in FIG. 4B, another electronic component is mounted on the component mounting surface 22 s of the printed wiring board 22 using a surface mount component mounter, and the solid adhesive 24 is applied to the electronic component 21. It is mounted in the mounting area. In the present embodiment, a solid adhesive is mounted at a position overlapping the four corners of the electronic component 21 in a direction intersecting the electrode forming surface 21s of the electronic component 21 (adhesive mounting step).

  Next, as illustrated in FIG. 4C, the electronic component 21 in which the solder bump 23 is bonded to each electrode 21 a is mounted on the printed wiring board 22. At this time, each solder bump 23 is bonded to the electrode 22a of the printed wiring board 22, and the four corners of the electronic component 21 are mounted on the solid adhesive 24 in a direction crossing the electrode forming surface 21s and the component mounting surface 22s ( Component mounting process).

  Thereafter, as shown in FIG. 4D, the printed wiring board 22 is put into a reflow line, and the solder bumps 23, the solder paste 31, and the solid adhesive 24 are melted by heating at the time of reflow. Each is deformed by sinking due to the weight, and the electrodes 21a and 22a are bonded together, and the solid adhesive 24 is bonded to the corner of the electronic component 21 and the component mounting surface 22s of the printed wiring board 22. Thereafter, the solder bumps 23, the solder paste 31, and the solid adhesive 24 are cured by cooling after reflow, and the electronic component 21 is fixed to the printed wiring board 22 (heating and cooling step).

  Thus, according to the printed circuit board 20 and the manufacturing method of the printed circuit board 20 of the first embodiment, the solid adhesive 24 that is a substantially rectangular solid at room temperature is used as the reinforcing member. Similarly to the electronic component, the solid adhesive 24 can be easily mounted by the surface mount component mounter. Therefore, there is no process for applying a liquid adhesive by a syringe as described in Patent Document 1, so that the bonding strength of the electronic component 21 to the printed wiring board 22 can be reduced while suppressing an increase in price. Can be easily reinforced.

  Further, according to the printed circuit board 20 and the printed circuit board 20 manufacturing method of the first embodiment, the thermoplastic solid adhesive 24 having a melting temperature equal to or lower than the melting temperature of the solder bump 23 is used as the reinforcing member. Therefore, the solder bump 23 is melted before reflow and does not hinder the sinking caused by the weight of the electronic component 21, and the connection reliability of the solder bump 23 is not lowered.

  By the way, the liquid adhesive currently used in the market is troublesome in adjusting the coating amount and handling the material, and the workability is not good. Furthermore, the viscosity changes with time and temperature changes, and it is necessary to periodically check the situation even when used under the same conditions. In addition, a dedicated device is required for coating, and a dedicated process may be required.

  According to the printed circuit board 20 and the manufacturing method of the printed circuit board 20 of the first embodiment, since the solid adhesive is used instead of such a liquid adhesive, the operator adjusts the coating amount. There is no need to do. Since it is not affected by changes due to temperature or time, it is possible to mount a stable amount. In addition, handling is simplified and workability is improved, so man-hours can be reduced. Since there is no waste of the adhesive, the cost is reduced.

As a result, the electronic component 21 can be provided with a reinforcing structure to relieve the stress applied to the surroundings, and the bending resistance, drop resistance, and impact resistance can be improved. Can be realized. Therefore, the bonding strength of the electronic component 21 to the printed wiring board 22 can be efficiently reinforced.
[Second Embodiment]

  FIG. 5 is a view showing a printed circuit board according to the second embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along line VI-VI in the printed circuit board shown in FIG. FIG. 6 shows the printed circuit board before reflow. A printed circuit board 20A shown in FIGS. 5 and 6 is different from the first embodiment in that the printed circuit board 20 includes a solid adhesive 34 instead of the solid adhesive 24. Other configurations of the printed circuit board 20A are the same as those of the printed circuit board 20.

  In the present embodiment, the solid adhesive 34 is provided so as to cover the four corners of the electronic component 21 at the four corners of the edge of the electronic component 21 in order to reinforce the adhesive strength of the electronic component 21 to the printed wiring board 22. Yes. As shown in FIG. 6, the solid adhesive 34 includes a covering portion 34 a that covers a corner portion of the electronic component 21 and a protruding portion 34 b that protrudes from the electrode forming surface 21 s of the electronic component 21 toward the printed wiring board 22 at room temperature. It is a solid with an inverted L-shaped cross section and has an thermoplasticity. The melting temperature of the solid adhesive 34 is equal to or lower than the melting temperature of the solder bump 23. Therefore, the solid adhesive 34 is melted at the time of reflow and is deformed by sinking due to the weight of the electronic component 21, the covering portion 34 a is bonded to the corner of the electronic component 21, and the protruding portion 34 b is the printed wiring board 22. The electronic component 21 and the printed wiring board 22 are fixed by adhering to the component mounting surface 22s.

  The length H34 of the protrusion 34b in the solid adhesive 34 before reflowing (before melting), that is, the normal temperature length H34, is the electrode forming surface 21s of the electronic component 21 and the component mounting surface 22s of the printed wiring board 22 after reflowing (after melting). It is preferable that it is more than the space | interval H23a, and is 5 times or less of this space | interval. In other words, the height H34 before reflow of the protrusion 34b in the solid adhesive 34 is preferably equal to or higher than the height of the solder bump 23 after reflow, and is preferably equal to or lower than five times this height. According to this, the solid adhesive 34 can be satisfactorily adhered to the corner of the electronic component 21 and the component mounting surface 22s of the printed wiring board 22 without inhibiting the sinking of the electronic component 21 during reflow. .

  In addition, as for the coating | coated part 34a of the solid adhesive 34, it is preferable that the surface which contact | connects the corner part of the electronic component 21 has adhesiveness. According to this, the deviation of the solid adhesive 34 can be prevented after being mounted on the electronic component 21.

  Next, a method for manufacturing a printed circuit board according to the second embodiment of the present invention will be described. FIG. 7 is a diagram showing a method for manufacturing a printed circuit board according to the second embodiment of the present invention.

  First, as shown in FIG. 7A, a printed wiring board 22 having a mounting area for mounting the electronic component 21 is put into a component mounting line, and a solder paste 31 is placed on the wiring electrode 22a on the component mounting surface 22s side. Is printed (preparation step).

  Next, as illustrated in FIG. 7B, the electronic component 21 in which the solder bump 23 is bonded to each electrode 21 a is mounted on the electronic component mounting region on the printed wiring board 22. At this time, each solder bump 23 is bonded to the electrode 22a of the printed wiring board 22, and the electrode forming surface 21s of the electronic component 21 is mounted facing the mounting region of the printed wiring board 22 (component mounting process).

  Next, as shown in FIG.7 (c), the solid adhesive 34 is mounted in the corner of the electronic component 21 using the mounter for surface mount components (adhesive mounting process).

  Thereafter, as shown in FIG. 7D, the printed wiring board 22 is put into a reflow line, and the solder bumps 23, the solder paste 31, and the solid adhesive 34 are melted by heating at the time of reflow. The electrodes 21a and 22a are bonded to each other by being deformed by the sinking due to the weight. Further, the covering portion 34 a of the solid adhesive 34 is bonded to the corner of the electronic component 21, and the protruding portion 34 b is bonded to the component mounting surface 22 s of the printed wiring board 22. Thereafter, the solder bumps 23, the solder paste 31, and the solid adhesive 34 are cured by cooling after reflow, and the electronic component 21 is fixed to the printed wiring board 22 (heating and cooling step).

The printed circuit board 20A and the printed circuit board 20A manufacturing method of the second embodiment can provide the same advantages as the printed circuit board 20 and the printed circuit board 20 manufacturing method of the first embodiment.
[Third Embodiment]

  FIG. 8 is a view showing a printed circuit board according to the third embodiment of the present invention, and FIG. 9 is a cross-sectional view taken along line IX-IX in the printed circuit board shown in FIG. FIG. 9A shows the printed circuit board before reflow, and FIG. 9B shows the printed circuit board after reflow.

  A printed circuit board 20 </ b> B shown in FIGS. 8 and 9 includes a reinforced electronic component 40 according to the embodiment of the present invention instead of the electronic component 21 and the solid adhesive 24 in the printed circuit board 20. It is different from 1st Embodiment by the structure provided with printed wiring board 22B instead. Other configurations of the printed circuit board 20B are the same as those of the printed circuit board 20.

  The printed wiring board 22B is different from the first embodiment in that the printed wiring board 22 further includes an electrode 22b on the component mounting surface 22s for joining to the reinforcing member 44 of the reinforcing electronic component 40. Yes. Other configurations of the printed wiring board 22B are the same as those of the printed wiring board 22. A solder paste 31 is applied to the electrodes 22b of the printed wiring board 22B.

  The reinforcing electronic component 40 includes an electronic component 21, a solder bump 23, and a reinforcing member 44. In addition, since the electronic component 21 and the solder bump 23 are as above-mentioned, description is abbreviate | omitted.

  In the present embodiment, the reinforcing members 44 are provided so as to cover the four corners of the electronic component 21 at the four corners of the edge of the electronic component 21 in order to reinforce the bonding strength of the electronic component 21 to the printed wiring board 22B. . As shown in FIG. 9A, the reinforcing member 44 includes a covering portion 44a that covers a corner portion of the electronic component 21, and a protruding portion 44b that protrudes from the electrode forming surface 21s of the electronic component 21 toward the printed wiring board 22B. And has an inverted L-shaped cross section. As a material of the reinforcing member 44, a metal (for example, Au, Sn, etc.) capable of joining solder is used. In addition, other metals (for example, Cu, Fe, etc.) may be used for the material of the reinforcing member 44, and plating processing (for example, Au, Sn, Ni, etc.) may be performed.

  The covering portion 44a is joined to the corner of the electronic component 21 with an adhesive or the like. Solder 45 is joined to the end face of the protruding portion 44b facing the printed wiring board 22B. As shown in FIG. 9B, the solder 45 is melted at the time of reflow, and the protrusion 44b of the reinforcing member 44 and the electrode 22b of the printed wiring board 22B are joined together with the molten solder paste 31 similarly. .

  The length H44 of the protrusion 44b of the reinforcing member 44 is preferably equal to or less than the distance H23a between the electrode forming surface 21s of the electronic component 21 after reflow (after melting) and the component mounting surface 22s of the printed wiring board 22B. Further, the sum of the length H44 of the protruding portion 44b of the reinforcing member 44 and the length 45 of the solder 45 before reflowing (before melting), that is, the length H45 at room temperature, is the electrode forming surface 21s of the electronic component 21 after reflowing and the printed wiring. The distance H23a between the plate 22B and the component mounting surface 22s is preferably greater than or equal to H23a. In other words, the length H44 of the protruding portion 44b of the reinforcing member 44 is preferably equal to or less than the height of the solder bump 23 after reflow, and the length H44 of the protruding portion 44b of the reinforcing member 44 and before the solder 45 is reflowed. The total length with the length H45 is preferably equal to or greater than the height of the solder bump 23 after reflow. According to this, it is possible to satisfactorily fix the corner of the electronic component 21 and the component mounting surface 22s of the printed wiring board 22B without inhibiting the sinking of the electronic component 21 during reflow.

  Next, a procedure for mounting the reinforcing electronic component 40 on the printed wiring board 22B, that is, a method for manufacturing a printed circuit board according to the third embodiment of the present invention will be described. FIG. 10 is a diagram illustrating a method of manufacturing a printed circuit board according to the third embodiment.

  First, as shown in FIG. 10A, a printed wiring board 22B having a mounting area for mounting the reinforcing electronic component 40 is put into a component mounting line and placed on the wiring electrodes 22a and 22b on the component mounting surface 22s side. The solder paste 31 is printed (preparation process).

  Next, as shown in FIG. 10B, the reinforced electronic component 40 is mounted on the printed wiring board 22B using a surface mount component mounter. At this time, each solder bump 23 is connected to the electrode 22a of the printed wiring board 22B, and the solder 45 bonded to the protruding portion 44b of the reinforcing member 44 is printed in a direction intersecting the electrode forming surface 21s and the component mounting surface 22s. It is mounted so as to overlap with the electrode 22b of the plate 22B (component mounting process).

  Thereafter, as shown in FIG. 10C, the printed wiring board 22B is put into a reflow line, and the solder bump 23, the solder paste 31, and the solder 45 are melted by heating during reflow, and the weight of the electronic component 21 is increased. The electrodes 21a and 22a are joined by deformation due to the subsidence caused by the above, and the protruding portion 44b of the reinforcing member 44 and the electrode 22b of the printed wiring board 22B are joined. Thereafter, the solder bump 23, the solder paste 31, and the solder 45 are cured by cooling after reflow, and the electronic component 21 is fixed to the printed wiring board 22B by the reinforcing member 44 (heating and cooling step).

  Thus, according to the reinforced electronic component 40 of the third embodiment, since the reinforcing member 44 is bonded to the electronic component 21 in advance, the bonding strength of the electronic component 21 can be easily reinforced simultaneously with the mounting.

  Further, according to the reinforced electronic component 40 of the third embodiment, since the solder 45 is joined to the end face of the protruding portion 44b in the reinforcing member 44, it corresponds to the variation in the length of the protruding portion 44b in the reinforcing member 44. be able to.

Further, according to the printed circuit board 20B of the third embodiment, since the reinforced electronic component 40 is used, the reinforced electronic component 40 can be easily mounted by the surface mount component mounter in the same manner as other electronic components. It is possible to easily reinforce the bonding strength of the electronic component 21 to the printed wiring board 22B while suppressing an increase in price. Accordingly, the bonding strength of the electronic component 21 to the printed wiring board 22B can be efficiently reinforced.
[Fourth Embodiment]

  Next, a printed circuit board according to a fourth embodiment of the present invention will be described. The printed circuit board according to the fourth embodiment is different from the third embodiment in that the printed circuit board 20B includes a reinforcing electronic component 40A instead of the reinforcing electronic component 40. Other configurations of the printed circuit board according to the fourth embodiment are the same as those of the printed circuit board 20B.

  FIG. 11 is a diagram showing a reinforced electronic component 40A according to the fourth embodiment of the present invention. FIG. 11A shows a view of the reinforcing electronic component 40A as viewed from the electrode forming surface side, and FIG. 11B shows an XI-XI in the reinforcing electronic component 40A shown in FIG. 11A. A cross-sectional view along the line is shown.

  The reinforced electronic component 40 </ b> A includes the electronic component 21, the solder bump 23 bonded to the electrode 21 a on the electrode forming surface 21 s of the electronic component 21, and the solid bonded to the corner electrode forming surface 21 s at the edge of the electronic component 21. And an adhesive 24. The details of each are as described above.

Also with the reinforced electronic component 40A of the fourth embodiment, the same advantages as the reinforced electronic component 40 of the third embodiment can be obtained. Further, the printed circuit board of the fourth embodiment can obtain the same advantages as the printed circuit board 20B of the third embodiment.
[Fifth Embodiment]

  Next, a printed circuit board according to a fifth embodiment of the present invention will be described. The printed circuit board according to the fifth embodiment is different from the third embodiment in that the printed circuit board 20B includes a reinforced electronic component 40B instead of the reinforced electronic component 40. Other configurations of the printed circuit board of the fifth embodiment are the same as those of the printed circuit board 20B.

  FIG. 12 is a diagram showing a reinforced electronic component 40B according to the fifth embodiment of the present invention. FIG. 12 shows a cross-sectional view of the same portion of the reinforced electronic component 40B as in FIG. 11B.

  The reinforcing electronic component 40B is different from the fourth embodiment in that the reinforcing electronic component 40A includes a solid adhesive 34 instead of the solid adhesive 24 in the reinforcing electronic component 40A. Other configurations of the reinforcing electronic component 40B are the same as those of the reinforcing electronic component 40A. The solid adhesive 34 is coupled to the electronic component 21 so as to cover the corners at the edge of the electronic component 21. The details of the solid adhesive 34 are as described above.

  Also with the reinforced electronic component 40B of the fifth embodiment, the same advantages as the reinforced electronic component 40 of the third embodiment can be obtained. Further, the printed circuit board of the fifth embodiment can obtain the same advantages as the printed circuit board 20B of the third embodiment.

  The present invention is not limited to the above-described embodiment, and various modifications can be made.

  In the present embodiment, the solid adhesives 24 and 34 are joined to the four corners at the edge of the electronic component 21, but the joining positions of the solid adhesives 24 and 34 with respect to the electronic component 21 are not limited to this embodiment. Absent. For example, as long as the solid adhesive 24 is an electrode forming surface 21 s facing the printed wiring board 22 in the electronic component 21, the solid adhesive 24 may be bonded to any position on the edge surrounding the electronic component 21, or the solid adhesive 24. May be bonded to the central portion of the electrode forming surface 21s to which the solder bumps 23 are not bonded. The solid adhesive 34 may also be bonded to any position on the edge surrounding the electronic component 21.

  Similarly, in the present embodiment, the reinforcing member 44 is bonded to the four corners at the edge of the electronic component 21, but the bonding position of the reinforcing member 44 to the electronic component 21 is not limited to the present embodiment. FIG. 13 is a perspective view showing a reinforced electronic component 40C according to a modification. As shown in FIG. 13, a reinforcing member 54 having a reverse L-shaped cross section may be joined to the center of the edge of the electronic component 21. When the reinforcing member 44 and the reinforcing member 54 are combined, the reinforcing strength can be improved.

  As shown in FIG. 13, the reinforcing member 55 may be joined to the edge of the electronic component 21 and the reinforcing members 44 and 54 so as to surround the outer periphery of the electronic component 21. According to this, the curvature of the electronic component 21 can also be prevented.

It is a perspective view which shows the electronic device which concerns on 1st Embodiment. It is a figure which shows the printed circuit board which concerns on the 1st Embodiment of this invention. It is sectional drawing which follows the III-III line in the printed circuit board shown in FIG. It is a figure which shows the manufacturing method of the printed circuit board which concerns on the 1st Embodiment of this invention. It is a figure which shows the printed circuit board which concerns on the 2nd Embodiment of this invention. It is sectional drawing which follows the VI-VI line in the printed circuit board shown in FIG. It is a figure which shows the manufacturing method of the printed circuit board which concerns on the 2nd Embodiment of this invention. It is a figure which shows the printed circuit board which concerns on the 3rd Embodiment of this invention. It is sectional drawing which follows the IX-IX line in the printed circuit board shown in FIG. It is a figure which shows the manufacturing method of the printed circuit board which concerns on the 3rd Embodiment of this invention. It is a figure which shows the reinforced electronic component which concerns on the 4th Embodiment of this invention. It is a figure which shows the reinforced electronic component which concerns on the 5th Embodiment of this invention. It is a perspective view which shows the reinforced electronic component which concerns on a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Electronic device, 11 ... Computer main body, 12 ... Display unit, 13 ... Keyboard, 14 ... Power button, 15 ... Input operation panel, 16 ... Touch pad, 17 ... LCD, 18 ... Speaker, 20, 20A, 20B Print circuit Plate 21 ... electronic component, 21a ... electrode, 21s ... electrode forming surface, 22, 22A, 22B ... printed wiring board, 22a, 22b ... electrode, 22s ... component mounting surface, 23 ... bump, 24, 34 ... solid adhesive, 34a ... covering part, 34b ... protruding part, 31 ... solder paste, 40, 40A, 40B ... reinforcing electronic component, 44,54,55 ... reinforcing member, 44a ... covering part, 44b ... protruding part, 45 ... solder.

Claims (13)

Preparing a printed wiring board having a mounting area for mounting electronic components; and
An adhesive mounting step of mounting a solid adhesive on the mounting region of the printed wiring board prepared by the preparation step;
A component in which the electronic component is mounted on the printed wiring board that has undergone the adhesive mounting step, and the electrode forming surface is mounted on the solid adhesive in a direction crossing the electrode forming surface of the electronic component. Mounting process;
A heating step of reflow heating the printed wiring board that has undergone the component mounting step;
A method for producing a printed circuit board, comprising: Preparing a printed wiring board having a mounting area for mounting electronic components; and
Mounting the electronic component on the printed wiring board prepared by the preparation step, and mounting the electronic component with the electrode forming surface facing the mounting region of the printed wiring board; and
An adhesive mounting step of mounting a solid adhesive on the edge of the electronic component that has undergone the component mounting step;
A heating step of reflow heating the printed wiring board that has undergone the adhesive mounting step;
A method for producing a printed circuit board, comprising: In the adhesive mounting step, the solid adhesive is characterized by using a thermoplastic adhesive that is a substantially rectangular solid at room temperature,
The manufacturing method of the printed circuit board of Claim 1. In the adhesive mounting step, the solid adhesive has a height at a normal temperature in a direction intersecting the electrode forming surface of the electronic component that is equal to or greater than an interval between the electronic component and the printed wiring board after the heating step. It is characterized by using an adhesive that is
The manufacturing method of the printed circuit board of Claim 3. In the adhesive mounting step, the solid adhesive has a covering portion that covers an edge portion of the electronic component at room temperature and a protruding portion that protrudes from the electrode formation surface of the electronic component toward the printed wiring board. A thermoplastic adhesive which is a solid having an inverted L-shaped cross section is used.
The manufacturing method of the printed circuit board of Claim 2. In the adhesive mounting step, the solid adhesive has the length of the protruding portion in the direction intersecting the electrode forming surface of the electronic component at room temperature, and the electronic component and the printed wiring after the heating step. It is characterized by using an adhesive that is more than the distance from the plate,
A method for manufacturing a printed circuit board according to claim 5. In the component mounting step, the electronic component is mounted on the printed wiring board using bumps for connecting electrodes on the electrode forming surface of the electronic component,
In the adhesive mounting step, the solid adhesive is characterized by using an adhesive having a melting temperature equal to or lower than the melting temperature of the bump.
The manufacturing method of the printed circuit board of any one of Claims 1-6. An electronic component having an electrode on the electrode forming surface;
A bump bonded to the electrode of the electronic component;
A solid adhesive that is a substantially rectangular solid at room temperature and has thermoplasticity, and is bonded to the electrode forming surface of the electronic component;
Reinforced electronic components comprising An electronic component having an electrode on the electrode forming surface;
A bump bonded to the electrode of the electronic component;
The electronic component has a reverse L-shaped solid section having a covering portion that covers an edge of the electronic component at room temperature and a protruding portion that protrudes from the electrode forming surface of the electronic component, and has thermoplasticity. Solid adhesive bonded to the edge of
Reinforced electronic components comprising An electronic component having an electrode on the electrode forming surface;
A bump bonded to the electrode of the electronic component;
A reinforcing member joined to the edge of the electronic component, having a cross-sectional inverted L shape having a covering portion covering the edge of the electronic component and a protruding portion protruding from the electrode forming surface of the electronic component;
Reinforced electronic components comprising In a printed circuit board in which an electronic component having an electrode on the electrode forming surface facing the printed wiring board is mounted on the printed wiring board,
A bump for joining the electrode of the electronic component and the printed wiring board;
It is a substantially rectangular solid at room temperature and has thermoplasticity, provided between the electronic component and the printed wiring board, and after reflow overheating, the electrode forming surface of the electronic component and the printed wiring board A solid adhesive to be joined;
A printed circuit board comprising: In a printed circuit board in which an electronic component having an electrode on the electrode forming surface facing the printed wiring board is mounted on the printed wiring board,
A bump for joining the electrode of the electronic component and the printed wiring board;
It is a solid with an inverted L-shaped cross section having a covering portion that covers the edge of the electronic component at room temperature and a protruding portion that protrudes from the electrode forming surface of the electronic component toward the printed wiring board and has thermoplasticity. A solid adhesive that is provided at the edge of the electronic component and bonded to the edge of the electronic component and the printed wiring board after reflow overheating;
A printed circuit board comprising: In printed circuit boards with reinforced electronic components mounted on printed wiring boards,
The reinforcing electronic component is
An electronic component having an electrode on the electrode forming surface facing the printed wiring board;
A bump bonded to the electrode of the electronic component;
The cross section has an inverted L-shape having a covering portion that covers an edge portion of the electronic component and a protruding portion that protrudes from the electrode forming surface of the electronic component toward the printed wiring board, and is bonded to the edge portion of the electronic component A reinforcing member to be joined to the printed wiring board after reflow overheating;
A printed circuit board comprising:

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